Hymenolepis diminuta (H. diminuta) is a common parasite of rats and mice. It is very rare among humans. The life cycle of this parasite is completed in two hosts. Human beings are accidentally infected due to ingestion of infected fleas. Most   of the time human infections are asymptomatic. We report a case of Hymenolepis diminuta infection in a school-going 10-year-old girl from a coastal village in south Tamil Nadu. Demonstration of H. diminuta eggs in the stool is the important diagnostic tool. Absence of polar filaments confirms the Hymenolepis diminuta. Praziquantal is the drug of choice.